Delayed Newcastle disease virus replication using RNA interference to target the nucleoprotein.

Area of Science:

• * Virology
• * Molecular Biology
• * Poultry Science

Background:

• * Newcastle disease virus (NDV) causes substantial global economic and food losses in chickens annually.
• * Current vaccination strategies face limitations in developing countries, including cost, administration requirements, and cold chain dependency.
• * RNA interference (RNAi) presents a promising alternative antiviral approach by reducing viral replication.

Purpose of the Study:

• * To investigate the potential of microRNA (miRNA)-expressing constructs to target and suppress five key NDV structural protein genes (NP, P, M, F, L).
• * To evaluate the efficacy of targeting the nucleoprotein (NP) gene using miRNA in chicken embryo fibroblast cells (DF-1).

Main Methods:

• * Development and transient expression of miRNA-expressing constructs targeting specific NDV structural protein genes in DF-1 cells.
• * Assessment of NDV-induced cytopathic effects using cell counts in miRNA-expressing cells.
• * Measurement of cell survival and viral yield in DF-1 cells constitutively expressing the NP miRNA construct post-NDV infection.

Main Results:

• * Transient expression of miRNA targeting the NP mRNA in DF-1 cells conferred increased resistance to NDV-induced cytopathic effects compared to other targets.
• * Constitutive expression of the NP miRNA construct in DF-1 cells resulted in improved cell survival up to 48 hours post-infection (h.p.i).
• * A decreased viral yield was observed in DF-1 cells expressing the NP miRNA construct up to 24 h.p.i.

Conclusions:

• * Overexpression of miRNA targeting the NDV nucleoprotein (NP) gene can enhance cellular resistance to NDV infection.
• * This miRNA-based strategy shows potential for developing novel antiviral interventions against Newcastle disease in poultry.
• * Further research into in vivo applications may lead to effective resistance against NDV in live animals.